The invention relates to electric circuits and more particularly, to circuits where a current shunt-measuring device is required in combination with power components.
With reference to FIG. 1, a typical application of a current shunt is shown for an electronically speed controlled DC motor application. A jump bar 10 carries high current between two MOSFETs, 12 and 14. A current shunt 16 converts the current into voltage that is used by current measurement circuitry 18. A disadvantage of this approach is that the current measuring shunt 16 is mounted on a low power control printed circuit board (PCB) (not shown). Therefore, the high current through the shunt 16 (equal to the operating current of motor 20) produces heat that affects the operating temperature of the control circuitry. Also, additional PCB area is required for the high current traces.
Accordingly, there is a need to provide the function of a current measuring shunt and a high current connection bar so that no high current flows through the control PCB and no heat is added to the control PCB.
an object of the invention is to fulfill the need referred to above. In accordance with the principles of the present invention, this objective is achieved by providing a jump bar shunt structure including a base constructed and arranged to be mounted to a substrate and to function as a current shunt, a pair of first legs integral with the base and being constructed and arranged to be connected between terminals of at least two power devices such as MOSFETs, and a pair of second legs integral with the base and being constructed and arranged to be connected to a printed circuit board so as to define a current sensing connection.
In accordance with another aspect of the invention a power device assembly includes a substrate, a switching MOSFET mounted to the substrate, the switching MOSFET having a source leg; a reverse voltage protection (RVP) MOSFET mounted to the substrate, the RVP MOSFET having a source leg; and a jump bar shunt structure. The jump bar shunt structure includes a base; a pair of first legs integral with the base, one leg of the pair of first legs being connected to the source leg of the switching MOSFET and the other leg of the first pair of legs being connected to the source leg of the RVP MOSFET; and a pair of second legs integral with the base and being constructed and arranged to be connected to a printed circuit board so as to define a current sensing connection.
Other objects, features and characteristics of the present invention, as well as the methods of operation and the functions of the related elements of the structure, the combination of parts and economics of manufacture will become more apparent upon consideration of the following detailed description and appended claims with reference to the accompanying drawings, all of which form a part of this specification.